Researcher or Mad Man?

[Location: Kukuroo Mountain]

Getting off a tour bus, Ash had walked to the gate and stood before it.

*Sigh*

Ash heaved a long breath, stepping forward and pushing the gate open.

Expecting some form of a struggle to push it open, Ash had tensed his muscles and pushed hard.

Micro tears began forming within Ash's muscles from the intense strain caused by pushing the gate open. But within moments, four of the gates had been opened.

Ash walked through, continuing on his way to the manor. Not worried about any injuries he may have sustained from pushing himself so hard. His regeneration would surely make up for it.

Behind him, tourists had their mouths open in shock. A man with only one arm had managed to push that humongous gate open?

[Location: Zoldyck Manor]

Stepping inside the manor, Ash had walked through the hallways towards the dining room as it was about dinner time per his memories.

Making it to the dinner table, Ash had sat down nodding his head at Silva and Zeno.

Noticing Ash's missing left arm, Kikyo screamed "Oh dear, what happened to your arm my baby! Who did this to you I will kill them myself."

"I already killed it. I lost my arm 11 years ago; I was fighting a beast that was out of my league."

Looking around the table, Ash had noticed 3 new faces. A little silver haired boy, who was a tad bit similar looking to himself was staring at him.

"Mother? Is that big brother Ash, the one you always tell us about?" Asked the boy.

"Yes Killua, that's him. He's been gone for 11 years; he's been training away from home." Said Kikyo.

"Ash, these are your new siblings. Killua, the silver haired one. Kalluto, the black-haired boy right there. Milluki, the fat one." Kikyo said, point at each person she was describing.

"I am not fat! I'm just a bit plump mom." Said Milluki, protesting to his obesity.

"Hi" Said Killua.

Kalluto, the girlish looking boy, hadn't bothered to speak to Ash.

"Hello" Said Ash sweetly towards his new siblings.

"Why did you leave for so long brother?" Asked Illumi.

"I was training."

"Do I still have my room or is it gone?" Ash asked Illumi.

"It's there, but it's empty now I threw everything out."

In that very moment, to Illumi it seemed as if blood began flooding the room dripping off the furniture. An intense bloodlust began permeating out of Ash before it vanished, and a sweet smile instead replaced his dead expression.

"Oh, alright that's fine." Said Ash, now being friendly towards Illumi.

Killua, Milluki and Kalluto feeling this aura were glued to their seat, sweat dripping down their backs. Not realizing this seemingly sweet brother of theirs could be so cold and have such an intense bloodlust.

"I need a work phone, so I can take jobs." Ash said to Silva.

- 1 Week Later -

Killua was with Ash, training. Prior to this day, after dinner Killua had begged Ash to teach him some techniques.

Both Ash and Killua were holding a handstand, while Ash was reading a book holding himself up with one arm. This may have seemed strange to Killua as with one hand, Ash had still managed to read a book while holding himself up.

To Killua this was simply mind-blowing, while his only arm was occupied, the book was floating, and the pages were turning by themselves.

Nearing falling down from his handstand after noticing this, he asked Ash "How are you doing that?"

"Nen" Ash said in a monotone voice, focused on his biology book.

"Every minute the weight will increase, we're going for an hour." Said Ash

"Get into a plank position."

Killua now in a plank position asked, "What weight? This is a normal exercise; I'm not even wearing any weights."

Then a muffled groan was heard from Killua, invisible to him, Ash had utilized his strings of Nen and materialized a full suit of armor around himself and Killua giving it a heavy property by increasing its density.

- 21 Minutes Later-

Below Killua was a pool of sweat, his arms becoming flimsy threatening to give out at any moment. And that they did, he fell unconscious and within that same moment, but Ash had already moved and grabbed him and put him up on his shoulders.

"Come and bathe Killua" Ash said through a radio device, connected to the butlers.

Within a few minutes, a butler had arrived, bowed to Ash and then took Killua from his hands.

Going to his room, it had been barren but filled with books at this moment.

Ash had been getting servants to order any biology books they could possibly find.

Sitting on the cobblestone floor of his room, he had begun researching the genetic structure of many species.

Spotting an odd species in one the books, this species was named (Brain Leech) it was said to be a long thin parasite that drills into a person's brain and gain's control over their body.

It kills them in the process but seemingly puppeteers their corpses, having the ability to keep the same mannerisms as the person had before death.

This allows the leech to be hard to discover, but though dangerous it isn't invasive. Only one reported case has happened over the span of 40 years.

'A thin parasite that attaches to its hosts brain and controls them?' After reading this book, Ash had left the mountain and went to a black market.

Buying some slaves in the process, he had purchased 5 men and 5 women.

Taking them back to his room, he began experimenting on them. Materializing a string of Nen and creating a sharp tip, he plunged it into the first man's brain. Unfortunately, from this the man immediately died.

Ash wasn't disheartened from failure; life was always a case of failure until success. Moving the man's corpse aside, he began on another of the men. Before trying again, he had grabbed a book on the human anatomy.

While the slaves lie there in fear, gagged, unable to let out a scream from being tossed into a room with this evil man.

Ash was allowing butlers to feed the slaves regular food, non-poisoned food to be specific. From his research he had reached a hypothesis that a target of this must be in a good condition and not suffering from lack of brain function.

So, if a person was sleep deprived this would be hindered by their lack of motor function causing them to immediately die.

In theory, the ability to control a person's body after death was going to be good enough but he wanted to be able to control a person's motor functions while they were still living.

Killua, starting to develop a better relationship with Ash was met by his odd tendencies, not knowing if he had gone mad or could he just be a true researcher at heart.

But coming from a family of killers, he wasn't very bothered by this. Death wasn't something that could truly phase him, even at his young age. He was calm and collected, thinking logically in most situations.

Ash not having siblings in his past life was fine with Killua trying to get close to him, though he didn't really care about his sibling's feelings. He was just okay with it, even going as far as helping him when asked to.

A side effect of his first created Hatsu, he wasn't able to feel for others, lacking empathy.

But it wasn't as though the condition made him apathetic, it instead made him only not care for others feelings.

This stopped him from being emotionally connected to others. Although based on his character, he wouldn't have relations with emotions involved. Only having connections based solely on what he could gain.

For the next year, the slaves had been well fed, and had their body taken care of but they weren't going to leave at all.

Ash hadn't even promised them freedom if they lived, he explicitly told them he was going to kill them once he had achieved what he was hoping to.

Over this course of time from the year previous, Killua had been alongside Ash learning more and more about him. Believing his hobbies to be research, Killua had become his assistant. Learning assassination techniques from Ash in the meanwhile.

Ash had been asked, "Do you enjoy killing?"

Hearing this, Ash had thought back to before his death. Remembering himself standing in the midst of hundreds of corpses whose lives had no meaning whatsoever, only being used as tools for others.

"Listen Killua, the reaping of another life isn't an enjoyment but instead the greatest achievement. To be able to win a fight of life and death, you must be the sole victor and to be the sole victor you must be stronger."

"Killing is the outcome of strength, without killing you will be weak. If you are frightened to take the life of another, what happens if one who is willing to take lives fights you and they are weaker?"

"Do you merely hold them back while they continue to take attempts at your life? The one who kills is underhanded and sneaky, you will be hit with something you never seen coming from your moral point of view."

"Killing is my form of gratitude to life, it is the duality of living and dying that makes life worth living. The meaning of my life is to not lose my meaning. Don't live a life worth nothing, follow your heart at all times."

Killua seemed to have sensed a change in Ash's still heart before it went back to its originally coldness.

"Thank you big brother, I'll remember this." Killua said, feeling something different about Ash.

After this day, Killua stopped coming to Ash's room to learn from him seemingly not even interested in learning new techniques.

Ash wasn't bothered by this as he didn't care about Killua coming to learn from him to begin with.

*RING*RING*

He had dialed up Illumi's number.

"Yes?" Said Illumi on the other line.

"Can you come be an assistant for me?"

"For how much?" Asked Illumi, only working for a price.

"25 million Jenny."

*CLICK*

The phone call had ended and within moments, Illumi had arrived at Ash's room.

"Already wired it, now I need you to hand me the books I ask for. Everything is already organized and arranged." Said Ash.

"Brain Anatomy"

Hearing this, Illumi handed the book to Ash.

"If I want them alive while being controlled I.. motor cortex.. how can I control it...." Ash began muttering to himself.

"What exactly are you trying to do?" Asked Illumi.

"Control people with my Nen while they're alive, it's simply a prerequisite before I control their corpses."

"Hoh, I can help you with that." Illumi said as I pulled out needles and threw one of them into a slave's head.

The slave began making erratic movements, seemingly controlled by Illumi.

"How? You didn't even attach the needle to their motor cortex..." Said Ash, confused as to how he controlled someone's movement's without controlling their motor cortex which is responsible for the body's movement.

- 2 Years Later -

Without ever making it an ability, without having to create an ability with conditions, Ash had learned how to control a person's movement after death and whilst alive.

Ash had shut himself in for 3 years to learn something without wanting to waste the creation of a Hatsu, he wasn't interested in setting conditions on himself to recreate this when he could take his time to do it without a Hatsu.

After finally mastering his new skill, Ash had turned on his work phone.

*DING*

[Assassinate: Oziah Mob Boss, Victor Oziah]

[Reward: 50 Million Jenny]

He had received a job immediately after turning his work phone on.

It was now time to take some jobs and gain EXP to gain new strength and possibly create new genes.

He had laid dormant for 3 years, it was time to unleash terror upon his targets. He was itching to kill, the research he had done had cause him to become obsessed with gaining new genes.

Unbeknownst to him, Adam had been watching his journey thus far.